Role of Interphase Barrier and Substructural Strengthening in Deformation Processed Composite Materials.

摘要

When alloys containing two ductile phases are subjected to large mechanical deformations, fine composite microstructures can be formed. These materials are referred to by a variety of terms including HDISC (heavily deformed in situ composites) and DPCM (deformation processed composite materials). They have been of particular interest due to the high strengths developed in them attendant with the extensive deformation processing. These strengths are much in excess of those expected on the basis of the single phase work hardening characteristics of the composite constituents. Two mechanisms have been proposed to explain the additional strength. One mechanism (interphase barrier strengthening attributes the incremental strengths developed in cold worked two phase materials to direct blocking of dislocation motion by the interphase boundaries. The other proposed mechanism (substructural strengthening) suggests that extra dislocation generation takes place as a result of the additional strain accomodation across interphase boundaries in single phase materials. Keywords: Composite materials, Deformation processing. (emk)